Partitioned table BigQuery (with custom field) - google-cloud-platform

Question

I can't find any examples that show how to write a JSON for a partitioned table using a custom field. Below is an example of how to specify a table partitioned by the type "DAY", but if I, in addition, would like to partition by a specific field - how would the JSON look like?
{
"tableReference": {
"projectId": "bookstore-1382",
"datasetId": "exports",
"tableId": "partition"
},
"timePartitioning": {
"type": "DAY"
}
}

Answer 1

Take a look at the API reference. The timePartitioning object currently supports the following attributes:
expirationMs
field
requirePartitionFilter
type
I won't copy/paste all of the comments here, but this is what it says for field:
[Experimental] [Optional] If not set, the table is partitioned by
pseudo column '_PARTITIONTIME'; if set, the table is partitioned by
this field. The field must be a top-level TIMESTAMP or DATE field. Its
mode must be NULLABLE or REQUIRED.
In your case, the payload would look like:
{
"tableReference": {
"projectId": "<your project>",
"datasetId": "<your dataset>",
"tableId": "partition"
},
"timePartitioning": {
"type": "DAY",
"field": "<date_or_timestamp_column_name>"
}
}
Alternatively, you can issue a CREATE TABLE DDL statement using standard SQL. To give an example:
#standardSQL
CREATE TABLE `your-project.your-dataset.table`
(
x INT64,
event_date DATE
)
PARTITION BY event_date;